A Phase 1/1b Study of the All-Oral Regimen CC-486 and Venetoclax in Acute Myeloid Leukemia

Venetoclax with azacitidine is the standard of care for newly diagnosed AML patients who are unfit for intensive induction chemotherapy. CC-486 is the oral formulation of azacitidine that is currently approved for post-induction chemotherapy maintenance in AML. In this single center open label, Phase 1/1b study, we investigated CC-486 and venetoclax in relapsed and refractory AML and newly diagnosed patients. In the dose escalation phase, patients received CC-486 at one of two cohorts (200 mg PO days 1-14 and 300 mg PO days 1-14). Venetoclax was given at the 400 mg/day PO regimen, for 28 days, after an initial intra-patient dose escalation per the standard of care. Using a 3+3 study design for these two cohorts, we determined the recommended dose of CC-486 to be 300mg daily on days 1-14. Most common adverse events included nausea, diarrhea, fatigue and cytopenias. The incidence of grade 3 or greater neutropenia or thrombocytopenia was 97% and 66%, respectively. There were no dose limiting toxicities in either cohort. The expansion phase of the study consisted of 10 additional relapsed and refractory patients and 16 patients with newly diagnosed AML. Responses were seen in all phases of the study, and six patients were successfully bridged to hematopoietic stem cell transplant. Correlative analyses including sequencing and metabolomics performed on patient samples suggested this regimen had a similar effect on leukemia stem cells compared with conventional (intravenous) azacitidine and venetoclax.